This study evaluated the bond strength of brackets to ceramic testing different etching times and light sources for photo-activation of the bonding agent. Cylinders of feldspathic ceramic were etched with 10% hydrofluoric acid for 20 or 60 s. After application of silane on the ceramic surface, metallic brackets were bonded to the cylinders using Transbond XT (3M Unitek). The specimens for each etching time were assigned to 4 groups (n=15), according to the light source: XL2500 halogen light, UltraLume 5 LED, AccuCure 3000 argon laser, and Apollo 95E plasma arc. Light-activation was carried out with total exposure times of 40, 40, 20 and 12 s, respectively. Shear strength testing was carried out after 24 h. The adhesive remnant index (ARI) was evaluated under magnification. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Specimens etched for 20 s presented significantly lower bond strength (p<0.05) compared with those etched for 60 s. No significant differences (p>0.05) were detected among the light sources. The ARI showed a predominance of scores 0 in all groups, with an increase in scores 1, 2 and 3 for the 60 s time. In conclusion, only the etching time had significant influence on the bond strength of brackets to ceramic.223245248Barghi, N., Fischer, D.E., Vatani, L., Effects of porcelain leucite content, types of etchants, and etching time on porcelaincomposite bond (2006) J Esthet Restor Dent, 18, pp. 47-52Nagayassu, M.P., Shintome, L.K., Uemura, E.S., Araújo, J.E., Effect of surface treatment on the shear bond strength of a resin-based cement to porcelain (2006) Braz Dent J, 17, pp. 290-295Shimada, Y., Yamaguchi, S., Tagami, J., Micro-shear bond strength of dual-cured resin cement to glass ceramics (2002) Dent Mater, 18, pp. 380-388Chen, J.H., Matsumura, H., Atsuta, M., Effect of different etching periods on the bond strength of a composite resin to a machinable porcelain (1998) J Dent, 26, pp. 53-58Guler, A.U., Yilmaz, F., Yenisey, M., Guler, E., Ural, C., Effect of acid etching time and a self-etching adhesive on the shear bond strength of composite resin to porcelain (2006) J Adhes Dent, 8, pp. 21-25Kasuya, K., Miyazaki, Y., Ogawa, N., Maki, K., Manabe, A., Itoh, K., Efficacy of experimental dual-cure resin cement for orthodontic direct bond system (2006) Orthod Waves, 65, pp. 107-111Meguro, D., Hayakawa, T., Kasai, K., Efficacy of using orthodontic adhesive resin in bonding and debonding characteristics of a calcium phosphate ceramic bracket (2006) Orthod Waves, 65, pp. 148-154Dall'igna, C.M., Marchioro, E.M., Spohr, A.M., Mota, E.G., Effect of curing time on the bond strength of a bracket-bonding system cured with a light-emitting diode or plasma arc light (2011) Eur J Orthod, 33, pp. 55-59Correr, A.B., Sinhoreti, M.A., Sobrinho, L.C., Tango, R.N., Schneider, L.F., Consani, S., Effect of the increase of energy density on Knoop hardness of dental composites light-cured by conventional QTH, LED and xenon plasma arc (2005) Braz Dent J, 16, pp. 218-224Cekic-Nagas, I., Egilmez, F., Ergun, G., The effect of irradiation distance on microhardness of resin composites cured with different light curing units (2010) Eur J Dent, 4, pp. 440-446Thind, B.S., Stirrups, D.R., Lloyd, C.H., A comparison of tungstenquartz- halogen, plasma arc and light-emitting diode light sources for the polymerization of an orthodontic adhesive (2006) Eur J Orthod, 28, pp. 78-82Filipov, I.A., Vladimirov, S.B., Residual monomer in a composite resin after light-curing with different sources, light intensities and spectra of radiation (2006) Braz Dent J, 17, pp. 34-38Park, J.K., Hur, B., Ko, C.C., García-Godoy, F., Kim, H.I., Kwon, Y.H., Effect of light-curing units on the thermal expansion of resin nanocomposites (2010) Am J Dent, 23, pp. 331-334Price, R.B., Labrie, D., Rueggeberg, F.A., Felix, C.M., Irraciance differences in the violet (405 nm) and blue (460 nm) spectral ranges among dental light-curing units (2010) J Esthet Restor Dent, 22, pp. 363-377Yen, T.W., Blackman, R.B., Baez, R.J., Effect of acid etching on the flexural strength of a feldspathic porcelain and a castable glass ceramic (1993) J Prosthet Dent, 70, pp. 224-233Reynolds, I.R., Composite filling materials as adhesives in orthodontics (1975) Br Dent J, 138, p. 83Rueggeberg, F., Contemporary issues in photocuring (1999) Compend Contin Educ Dent, (SUPPL.), pp. 4-15Olsen, M.E., Bishara, S.E., Boyer, D.B., Jakobsen, J.R., Effect of varying etching times on the bond strength of ceramic brackets (1996) Am J Orthod Dentofacial Orthop, 109, pp. 403-409Sant'anna, E.F., Monnerat, M.E., Chevitarese, O., Stuani, M.B., Bonding brackets to porcelain - in vitro study (2002) Braz Dent J, 3, pp. 191-196Canay, S., Hersek, N., Ertan, A., Effect of different acid treatments on a porcelain surface (2001) J Oral Rehabil, 28, pp. 95-101